Interconnection of two very weak AC systems by synchronverter based HVDC

International audienceIn this paper, the HVDC emulation by the synchronverter concept is investigated for interconnection of two very weak AC systems. A specific tuning method for the parameters of the regulators based first on the sensitivity analysis of the system poles to the control parameters and, next, on their placement using residues. The use of the synchronverter control allowed us to improve the dynamic transmission capacity of a HVDC connection of two weak AC systems. This improvement is analyzed both from the point of view of the emulation that the synchronverter provides and from the dynamic (control) point of view. In addition to the analysis of the stability and capacity, the proposed control structure is also compared with the vector current control in terms of dynamic performances. The simulations tests in Matlab/Simulink are done with two very weak AC systems with a short-circuit ratio (SCR) of 1 interconnected by a HVDC line